How does BIOS flash work without CPU?

[SkyTerran]

A lot, if not most motherboards made in the last few years have a feature where you can flash a BIOS using a USB flash, without installing a CPU and memory. Wonder how does that work and can't find any information online. Does the motherboard have a cheap ARM SOC for this or does it work in a different way?

 

[SkyTerran]

It's as simple as software that is used to flash the chip is able to talk to the chip itself allowing parts of the chip to be overwrote with the upgrade file.

How do you run software without CPU?

 

[SkyTerran]

It will probably bypass the cpu

And run in the cloud?